CAJ | 학술논문

喀拉通克铜镍硫化物矿床3个主要含矿镁铁质岩体的主量元素、微量元素和铂族元素组成分析及母岩浆组成估算结果表明:3个岩体中不同类型岩石的主要氧化物含量的变化具玄武质岩浆结晶分异的特征;在MgO含量为10%～15%区间,SiO_2含量迅速增高;微量元素和稀土元素原始地幔标准化配分模式相似,具Nb和Ta亏损,K、Sr富集的特征.与1号和2号岩体相比,3号岩体中大离子亲石元素及轻稀土元素相对富集,(La/Yb)_N介于6.8～9.2之间,δEu显示轻微负异常,在460 m深度表现出Cu-Ni等成矿元素与SiO_2含量同时剧变的特征,铂族元素配分模式与2号岩体相似.上述结果显示,3个岩体可能是同源岩浆不同期次的产物,原始岩浆为高镁玄武岩浆.成矿岩浆演化过程中经历的岩浆分离结晶作用和富硅地壳组分混染可能是成矿岩浆硫饱和及硫化物熔离的主要诱因.
객랍통극동얼류화물광상3개주요함광미철질암체적주량원소、미량원소화박족원소조성분석급모암장조성고산결과표명:3개암체중불동류형암석적주요양화물함량적변화구현무질암장결정분이적특정;재MgO함량위10%～15%구간,SiO_2함량신속증고;미량원소화희토원소원시지만표준화배분모식상사,구Nb화Ta우손,K、Sr부집적특정.여1호화2호암체상비,3호암체중대리자친석원소급경희토원소상대부집,(La/Yb)_N개우6.8～9.2지간,δEu현시경미부이상,재460 m심도표현출Cu-Ni등성광원소여SiO_2함량동시극변적특정,박족원소배분모식여2호암체상사.상술결과현시,3개암체가능시동원암장불동기차적산물,원시암장위고미현무암장.성광암장연화과정중경력적암장분리결정작용화부규지각조분혼염가능시성광암장류포화급류화물용리적주요유인.
Three main ore-bearing mafic intrusions in the Kalatongke Cu-Ni sulfide deposit of Xinjiang were investi-gated for major element, trace element and platinum group element (PGE) compositions. MgO content of the parent magma was estimated by Fo values of the olivine and chemical compositions of the whole rock. The re-suits show that different types of rocks in the three intrusions show a systematical variation of major oxides with decreasing MgO contents, which is characteristic of basaltic magma crystallization, whereas SiO_2 contents dis-play rapid increase in the MgO contents range of 10% ～15%. The three intrusions exhibit similar Primitive Mantle (PM) -normalized distribution patterns of trace elements and rare earth elements, and significant Nb and Ta-depletion. The No. 3 imrusion is enriched in large ion lithophile elements (LILEs) and LREEs with the (La/Yb)_N ranging from 6.8 to 9.2, relative to the No. 1 and No. 2 intrusions, and shows a slight negative anomaly of δEu. The No. 3 intrusion shows a simultaneous content variation between SiO_2 and Cu-Ni as well as some other ore-forming elements at the depth of about 460 m, and exhibits similar PM-normalized distribution patterns of PGE to the No. 2 intrusion. It is inferred that the three mafic intrusions in the Kalatongke Cu-Ni ulfide deposit were probably formed by different stages of intrusions derived from the same source, and that their parent magma with MgO contents of about 9.3wt % underwent crystallization differentiation, crustal con-tamination and addition of a Si-rich oxide component. The main factors responsible for sulfur oversaturation and sulfide segregation might have been the addition of a Si-rich oxide component and the fractional crystallization.